attempts to flatten enumerate
Merge branch 'master' into flatten
flattens with explicit using
Removes IterBase in favor of templated usings
compress uses new type aliases
cycle uses new type aliases
dropwhile uses new type aliases
enumerate uses new type aliases
filter uses new type aliases
filterfalse uses new type aliases
groupby uses new type aliases
slice uses new type aliases
sorted uses new type aliases
takewhile uses new type aliases
comments expanded